Excavating machine



Nov. 3 1925.

R. R. DOWN IE EXCAV'A'I'ING MACHINE RRDon m INVENTOR ATTORNEY Nov.3,1925;

R. R. DOWNIE EXCAVATING MACHINE 5 sheets-sheet 2 Filed Jan. 28, 1925ATTORNEY Nov. 3 1925.

R. R. DOWNIE EXCAVATING MACHINE 3 Sheets-Sheet 5 Filed Jan 28, 1925INVENTOR WITNESSES Patented 3, 1925.

UNITED STATES P \'1'1 .=.1-1'r OFFICE.

ROBERT REX DOwNIE, OF vI BEAVER. FALLS, PENNSYLVANIA, ASSIGNOR TOKEYSTONE DRILLER COMPANY, OF BEAVER FALLS, PENNSYLVANIA, A CORPORATIONOF PENNSYLVANIA.

EXGAVATING MACHINE.

Application filed January 28, 1925. Serial 1T0. 5,249.

To all whom itmag concern A Q Be it known that I, ROBERT Rnx DoWNIn, acitizen of the United States, residing at Beaver Falls, in the county ofBeaver and .6 State of Pennsylvania, have invented a new and usefulExcavating Machine, of which the following is aspecification.

This'invention relates to excavating 1nachines, and particularlytothose' of the drag stick, ditcher type, such as that disclosed in UnitedStates Patent No. 1,511,114, granted to me October 7, 1924,.a'nd itconsists primarily in'an improved device for controlling the position ofthe ditcher scoop. The object of the present inventionis to provide animproved construction which will permit a much greater latitude 1n thepositioning-or spotting of the loaded scoop when elevated as fordumping, and will per 90 mit greater positiveness andaccuracy incontrolling the position of the scoop within that range than isotherwise feasible.

To the attainment of the foregoing, the invention comprises amodification in the form of the upper endof the ditcher stick,

and of the means connecting the same to the hoisting line, thepoint' atwhich the hoisting line stress is delivered to the upper end of thestick, whenever there'is a change in the inclination of the boom, or inthe angle between the boom and the "stick. In the specific embodiment ofthe invention, which is herein described and illustrated, thisconnecting means comprises a flexible member in lieu of the stifl'connecting bar previously used, and the upper end of the stick isextended in the plane of its up and down movement to form an upwardlybowed head having a groove in its u er face for receiving and guidingsaid flexible member, andadapted to maintain, at all times, a suificientdistance between the line in which the hoisting force is applied and thepivotal connection of the stick with the boom.

The specific construction of the invention, as wellas its advantages andits-mode of operation, willbe more fully explained in the detaileddescription which follows, which is to be read in connection with theaccompanying drawings, illustrating one embodiment of the invention.

In the drawings:

Figure 1 is a side elevation of the invention showing the boom raised,

so asto effect a shifting ot above the Figure 2 is a similar viewshowing the boom lowered, and the scoop at its outermost position, as atthe beginning of an excavating operation.

Figure 3 is a similar View showing the position of the ditcher stick andscoop after they have been drawn in.

The invention is shown in connection with h an excavating machine 1,having a mast 2, which is connected thereto by a pair of verticallyalined pivots 3. A boom 4 is pivotal- 1y connected, as at 5, to thelower end of the mast, and is adapted to be moved upwardly anddownwardly about its pivot 5, and the boom may be swung laterally withthe mast 2 about the pivots 3. The outer end of the boom has extensionirons 6 secured thereto, the outer ends of which are traversedby a pivotbolt 7 for supportinga ditcher stick 8. A scoop 9 is'secured in theusual manner to the lower end of the ditcher stick, and. has a haulingbail 10 pivoted thereto to which isattached a hauling cable 11.

A bearing block 12 is secured to the inner side of theditcher stick nearits upper end for receiving the pivot bolt 7, and on the outer side ofthe ditcher stick somewhat block 12 is secured, a bearing block 13,which receives a pivot bolt 14 to which is connectedthe means 'forapplying force for hoisting the boom and scoop, and for spotting thelatter. In the present construction, this means comprises a flexibleelement, composed of a'series of links as indicated at 15, which isconnected at its outer. end to the pivot bolt 14, and is connected atits inner end to a pivot bolt 16, the latter havin a sheave l7 journaledthereon about w ich passes the hoisting cable 18. When the boom islowered,and the ditcher stick and scoop extended, as shown in Figure 2',the flexible element 15 is straight and in alinement with the hoistingline of tensio The upper end of the ditcher stick 8, however, isprovided with an upwardly bowed extension or head 19 disposed in theplane of movement of the ditcher stick as it moves about the pivot 7,and having in its upper face a groove 20 for engaging and guiding theflexible member 105 15 as the boom is raised and lowered, or the scoopand ditcher stick moved about the pivot 7. Thus, the extension or headfilling the scoop and for positioning preparatory to dumping the same iscontrolled entirely through the cables 11 and 18, as

: explained in the above mentioned patent.

In said patent, however, the sheave 17 was connected to the pivot bolt14 bya stifi connecting bar, and with such a construction when the ivotbolts 7 and 14 are properly located with respect to the line of tensionin the hoisting line to give the best results with the greatestconservation of power, under certain conditions the pivotbolt 7 will besubstantially in the line of pull between the cable 18 and the pivot 14,so that it is difiicu'lt to swing the scoop outwardly to gain thedesired spotting range. It is in order to prevent this condition withoutaltering the relative locations-of the pivot bolts 7 and 14 that I havedevised the pres ent construction, whereby, when the pivotbolt 14. is inwhat might be termed dead center osition, the flexible member '15 isengaged by the head 19 and swung upward ly, so as to shiftthe point ofapplication of the hoisting force, and increase its effective leverage,thus providing means for positively and effectively swinging t e scoopoutwardly by paying out the cable l1 and drawing in on of the elevationof the boom.

The effect of the construction herein described is to give the desireddegree of positiveness of action in bringing the scoop-to -the exactposition desired for dumplng' Thejs potting range is increased to abouttwice the range possible without this im provement, and without anyofl'setting disadvantages.

It is not feasibleto attain this increasedspotting range by altering therelative 10- cation of the pivots 7 and 14. Such alteration would resultin aprohibitive waste of power, or would sacrifice to a prohibitivedegree the outward reach of the stick when lowered and extended at thebeginning ofthe operation. The position of the pivots 7 and 1 1 isactually governed by considerations of power economy and necessarydigging travel or swee of the scoop, and can not, therefore, be a teredin order'to gain the' desired ,spotting range or outward dumping reach.

In excavators of this type, for example,- the pivot 14 islocated acertain distance above the pivot 7. The purpose of this relativearrangement is to cause the tension of 'the hoisting line 18 not only tosupport the the cable 18, regardless distance from t bail 10.

- Now,- in order that the least possible stick and attached parts, butalso to maintam a pull upon the upper end of the stick the boom actingas a stifli' link, to cause the stick to swing outwardly nearly intolongitudinal .alineinent with the boom. It, is

obvious that this initial reach is desired, and is, in fact,indispensable in starting the excavation down through alevel surface.The stick assumes and remains in this position of rest or equlhbrium,except as 'restrained -or retracted from it by the hauling line 11,which is attached to the bail 10 on 'the scoop. Digging is effectedbyfirst lowin the direction of the machine, and, with ally antagonistic,that is, the hauling line,

in order to draw thescoop toward the machine, .must first-offset by aportion of its own power, whatever outward thrust the hoisting line maybe exerting on the scoop through the stick as a lever. This antagonism,though objectionable in itself, because it reduces the net live poweravailable for actual digging, is, in practice, tolerable because itpermlts operating with cables only,

and permits three distinct positive movements of the scoo namely,inward, out- .ward and upwar with but two cables- Also it will be seenthat the measure of this antagonism lies in" the relative proportion oftwo spacings, the distance. from the stick pivot 7 to the ivot 14,-ascompared to the e pivot 7 to the pivot oi the v v amount of power may beneutralized in the digging operation b reason of the antagonism of theoppose pulls on the cables 11 and 18, the point '14 of. the hoistingline attachmentis located at the shortest possible distance above thefulcrum or pivot- 7 of the ditcher stick; that is, the shortest possible distance which will'constitute a-lever' arm of suflicient lengthto-cause thestick, when in equilibrium, to bein the outward position,which is necessary for starting the excavation; and thepoint ofattachrange govern the location of the pivot 14 with reference to thepivot 7, both as to distance and direction, so that it can not bealtered inorder to secure the advantage of increased spotting or dumpingrange, but

the latter is secured in a practical manner by the present constructionwhich eflects a finely graduated and continuous shifting of the point atwhich the hoisting line stress is delivered to the upper end of thestick as the-boom is raised or lowered, and the ditcher stick movedoutwardly or inwardly about the pivot 7.

While I have shown and described specifically the various features oftheinven tion and the advantages thereof, it is to be understood that theseare subject to modification as long as such modification does notinvolve any material departure from the principles upon which theoperation of the invention is based. It is, therefore; my intention toinclude, all such modifications within the scope of the appended claims.

What is claimed is:

1. In an'excavatingmachine, the combination of a boom pivotally mountedfor up and down movement a ditcher stick pivoted to the outer end of theboomland depending therefrom, a hoisting line, a flexible memberconnecting the hoisting line to the stick above the pivotal connectionof the latter with the boom, the" upper end of the stick having aportion engageable with said flexible member to displace the innerportion thereof as the lower end of the stick moves toward the boom,thereby increasing the distance between the ditcher stick pivot and thepoint at which the hoistin is delivered to the upper end 0 the stick.

2. In an excavating machine, the combination of a boom pivotally mountedfor up and down movement, a ditcher stick pivoted to the outer end ofthe boom, a hoisting line,

and a series of interconnected links connect ing the hoisting line tothe upper end of the stick so as to transmit the tension of the hoistingline thereto, the up er end of the stick having means associatetherewith for deflecting the links upwardly as the stick.

approaches the boom,'and thereby continuously increasing the distancebetween the ditcherstick pivot and the line throu h which the hoistingforce is. delivered to t e upper end of the stick.

3. In an excavating machine, the combination of a boom pivotally mountedfor up and down movement, a ditcher stick pivote to the outer end of theboom, a hoistin line, and a flexible member connecting the oisting linewith the upper end 0 the stick, sald stick having an extended upper'portion engageable with the flexible member throughout a portion of itslength to increase the distance between the hoisting line of tension andthe ditcher stick pivot as the ditcher stick swings toward the boom.

line stress ture.

nation of a boom pivotally mounted for up and down movement, a ditcherstick pivoted to the outer end of the boom, a hoisting line, andaflexible member connecting the hoisting line with the outer side ofthestick near'its upper end, said upper end having an extension upwardlyand inwardl in the plane of. movement ofthe stick about its pivot andenga cable with successive oints along thelengt of said flexible mem erto increase the distance between the stick pivot and the point ofapplication of'the hoistingforce as the stick. swings inwardly and astheconnection between it and the flexible member a proaches nearer toalinement with the ditcher stick pivot and the inner end of the hoistingline. 5. In an excavating machine, the combination of a boom pivotallymounted for up and down movement, a ditcher stick pivoted Y to the outerend of the boom and depending therefrom, a hoisting line, a flexiblemember connecting the hoisting line to the stick above the pivotalconnection with the latter to the boom, the upper end of the stick having an upwardly wed portion extendin upwardly and inwardly in the lane 0movement of said stick about its pivot, said bowed portion beingengageable with the flexible member' to deflect the same up wardly asthe angle between the stick and the hoisting line of tension isdecreased. 6. In an excavating machine,the combination of a boompivotally mounted for up and down movement, a ditcherstick .pivotetherefrom, a hoistin line, a flexib e member 'connectin the 'oistingline with the upper end 0 the stick above the pivotal connection ofthelatter with the boom, the

to the outer end of the boom and de ending upper end of said stick beingformed with an upwardly bowed portion extending up ward y and inwardlyin the plane of movement of the stick about its ivot, said extendedgressively increase the distance between the ditcher stick ivot and thepointat which rtion being engageab c with successive, points along thelength of said flexi-v ble member to displace the same andprothehoisting me stress is delivered to the upper end of the stick as theangle between the latter and the hoistin line decreases said extendedportion at to upper end 0 its u per face said exible member. 7 1

In testimon that-I claim the fore ing as my own, I ave hereto afiixed mys1gna- ROBERT REX DOWNIE.

the stick being rovided with a oove in 3 or receiving an guiding

